1. Technical Field
Embodiments of the invention relate to thermal interface materials and more particularly to methods of processing thermal interface materials to allow easy pick and placement of the thermal interface materials.
2. Description of Related Art
Packaging of a mixed-die multi-chip package may involve one or more types of thermal interface materials (TIMs), e.g. solder TIM and elastomer TIM. To simplify the packaging process and reduce costs, it would be desirable to use a same method to assemble both types of thermal interface materials. One method involves the use of a vacuum nozzle tool to pick a TIM pre-form from a pocketed carrier tape and placing the TIM pre-form on the backside of a semiconductor die. While this method is suitable for solder TIM, problems arise when the same method is applied to elastomeric pad-type TIMs.
Most elastomeric pad-type TIMs are adhesive or tacky on both sides to enhance attachment of the TIM to a mating surface of the semiconductor die and to increase thermal contact between the TIM and the mating surface. This adhesive property, however, hinders pick and place ability of the tool and requires significant modifications to the tool to overcome the adhesive property. Although a non-adhesive/non-tacky coating (e.g. talc film) can be applied instead to the TIM, this is undesirable as the non-adhesive coating contributes to poor thermal contact and thermal performance.